The present invention relates in general to fork lift trucks and, more particularly, to an improved straddle arm for supporting the forward end of such trucks while permitting free movement of forks carried by the trucks. While the present invention is generally applicable to fork lift trucks, it is described herein with reference to a rider reach fork lift truck, for which it is particularly applicable and initially being used.
Rider reach fork lift trucks are typically provided with a pair of forwardly extending straddle arms mounted outside the forks where they do not impede the lowering of the forks, and any load supported upon the forks, to the floor. The straddle arms carry one or more wheels to support the weight of the truck of course including any load carried by the forks. In prior art trucks, straddle arms are attached to a truck by means of a lateral member which is typically a box structure formed by a pair of L-shaped or U-shaped steel components welded together.
FIG. 1 shows one example of prior art straddle arm construction. A straddle arm 1 is welded to a lateral member 2 which in turn is welded to a mast assembly 3 at the forward end of a power unit 4. The lateral member 2 is made of two components which are welded together at the front 5 of the lateral member 2 and at the rear 6 of the lateral member in substantially the same manner. The truck supporting force applied to wheels at the forward end of the straddle arm 1 results in a considerable amount of torque being transferred through the lateral member 2 to the mast assembly 3 such that the lateral member 2 must be substantial and securely welded .
There is an ongoing need to improve lift truck design to provide more efficient structure s and manufacturing techniques.